Method of making abrasive articles.



FRANCIS W. HIGGINS, 0F NIAGARA FALLS, NEW YORK, ASSIGNOR TO THE CARBORUN- DUM COMPANY, OF NIAGARA FALLS, NEW YORK, A CORPORATION OF PENNSYL- Paten'ted J an. 2, 11912.

VANIA. METHOD OF MAKING ABRASIVE ARTICLES.

1,013,651 Specification of Letters Patent.

No Drawing. Application filed February 28, 1907. Serial No. 359,911.

To all whom it may concern:

Be it known that I, FRANCIS W. HIGGINS, of Niagara Falls, Niagara county, New York, have invented a new and useful Method of Making Abrasive Articles, of

which the following is a full, clear, and

exact description.

My invention relates to the manufacture of ceramic bodies containing fluorin compounds, and especially to the manufacture of abrasive articles'by the use of a binder containing fluorin or a compound thereof. I have found that abrasive articles such as are formed of emery, carborundum, or granular or powdered abrasive material, held together by a binder, can be improved by using fluorin compounds as a constituent of the binder. It has been found, however, that when the shaped articles containing fluorin in the binder are fired in a kiln, a deterioration occurs, either by the action of the kiln gases, or by reason of certain reactions which occur within the article which liberate certain gases, or perhaps, from both causes combined. This deterioration seri-- ously affects the strength and value of the articles, and to a considerable extent neu tralizes the advantages which would otherwise result from the use of a binder containing fluorin. I have discovered that this deterioration in firing can be overcome and the value of the fluorin-containing binder can be retained, by coating the articles, after they have been shaped from the mixture of abrasive material and binder, and before firing, with a glaze-forming layer or coating which is substantially impervious to gases-both kiln gases and also any gases which may form within the articles.

In practice I have found that the desired results are obtained by the use of a coating or glaze consisting of a wet mixture of kaolin and feldspar, for example, 3 in the proportion of one part of kaolin to four parts of feldspar, although I do not, in my broader claims, limit myself to the use of this particular composition, as there are various others which can be used. The coating composition should, however, beone which will fuse at a temperature'below the vitrification point of the fluorin-containing binder; it should be substantially impervious to gases; and it should be resistant or inert to the act-ion of fluorin gases. The shaped articles having been painted or coated with the'protective coating of the character described, are fired in the usual manner.

While I am not able to state with certainty the exact manner in which the protective coating acts, daily practical use of such coating'has demonstrated the fact that it does act with great efficiency to prevent deterioration in firing and in preserving the valuable properties of the fluorin-containing binder.

'I claim 1. The method of making abrasive articles, which consists in shaping the article from a mixture of an abrasive material and a binder containing fluorin, coating the shaped article with a coat or layer which is substantially impervious to gases, and then firing; substantially as described.

2. The method of making abrasive articles, which consists in shaping the article from a mixture of an abrasive material and a binder containing fluorin, coating the shaped article with a coat or layer which is resist-ant to fluorin gases, and then firing; substantially as described.

3. The method of making abrasive articles, which consists in shaping the article from a mixture of an abrasive material and a binder containing fluorin, coating the shaped article with a coat or layer which will fuse at a kiln temperature below the vitrifying point of the binder, and then firing; substantially as described.

4. The method of making abrasive articles, which consists in shaping the article from a mixture of an abrasive material and my hand.

FRANCIS W. HIGGINS. Witnesses:

F. J. TONE, ASHMEAD G. RODGERS. 

